Lots of people enjoy having an elaborated work of art (like the ones shown in this posting) because they know how important it is to have a work of art in their body that actually people can enjoy looking at it and also can be accepted and admired by those who truly know body art.
Many people choose to have an elaborated work of art like those who get robotic parts because they like how amazing it looks, and other simple enjoy perfection instead of a tattoo that looks simple. A tattoo artist with skills developed by experience and knowledge can achieve what it takes to create such amazing work.